ST604 Kirklareli - Üsküpdere

The ST604 Kirklareli–Üsküpdere is a point-to-point hiking stage on the Sultans Trail in the Thrace region of Turkey, threading through the wooded foothills of the Istranca (Yıldız) Mountains. Rated expert because of remote terrain, sparse waymarking and rolling 200–500 m climbs, it links the provincial city of Kırklareli with the forest village of Üsküpdere on the historic Vienna-to-Istanbul cultural route.

About the ST604 Kirklareli - Üsküpdere

The ST604 is one stage in the Sultans Trail, a 2,500-kilometre long-distance walking route that runs from St. Stephen's Cathedral in Vienna to the Süleymaniye Mosque in Istanbul. The full trail crosses nine countries — Austria, Slovakia, Hungary, Croatia, Serbia, Bulgaria, Greece and Turkey — and commemorates the 1529 campaign of Sultan Süleyman the Magnificent, who left Istanbul on 10 May 1529 and reached Vienna 141 days later. Today the route is promoted as "a path of peace and a meeting place for people of all faiths and cultures," maintained by a Netherlands-based NGO, Sultans Trail — A European Cultural Route.

This particular stage sits deep in the Turkish leg of the trail, in the province of Kırklareli in Eastern Thrace. After the trail crosses from Bulgaria near Edirne, it bends north and east into the Istranca Mountains, a low forested range that separates the Thracian plain from the Black Sea coast. The ST604 connects the city of Kırklareli with Üsküpdere, a small village set among oak and beech woodland to the city's north. It is part of the International Walking Network (IWN), the classification reserved for routes of cross-border significance, and forms a single waypoint-to-waypoint link rather than a loop.

Because the Turkish Thrace section is far less trafficked than the European stages around Budapest or Belgrade, hikers should treat the ST604 as a self-reliant undertaking. Signage thins out once you leave the city limits, mobile coverage is patchy in the deeper forest, and resupply points are limited to the two settlements at either end. The reward is a quiet, history-soaked corridor of countryside that very few foreign walkers ever see. The Sultans Trail follows part of the E8 European long-distance path through this region, and while the European stages are walkable year-round, the trail's organisers note that the Bulgarian mountains just to the west can be impassable in deep winter — a reminder that conditions on either side of the frontier shift quickly with the seasons. For planning your daily stages, distances and overnight stops, you can map the whole thing in the HikeLoad route planner before you set off.

Route Overview & Stages

The ST604 is a single named stage, but it helps to break it into navigational segments between the obvious landmarks. The figures below are practical estimates for the Kırklareli–Üsküpdere corridor; the Sultans Trail organisation publishes the authoritative GPX tracks, and you should carry those on a GPS device.

Exact distance for the stage is not officially published as a round number, so budget for a roughly 18-kilometre walking day on foot. The cumulative climb is modest by alpine standards — around 500 metres — but the expert rating reflects navigation difficulty rather than steepness. There are no chairlifts, no refuges and few signposts once you enter the woods.

Highlights & Points of Interest

• Hızırbey Mosque (Kırklareli) — The 16th-century Ottoman mosque at the heart of the old town, a fitting departure point on a trail named for a sultan.
• Kırklareli covered bazaar (Arasta) — A restored Ottoman market arcade, ideal for buying dried fruit, nuts and bread before you leave town.
• Kırklareli Museum — Houses Thracian-era finds, including artefacts from the nearby dolmens and tumuli that dot this borderland.
• Istranca (Yıldız) forest belt — One of the largest broadleaf forests in European Turkey, dominated by oak, beech and hornbeam, and a haven for migratory birds.
• Roadside springs and çeşme fountains — Traditional stone fountains appear along the old village tracks; several still run clear, though you should treat or filter the water.
• Dupnisa Cave (regional detour) — A short drive north, this is the only show cave in Turkish Thrace, with underground rivers and chambers worth a rest-day visit.
• Üsküpdere village core — A quiet farming hamlet with a small mosque, tea house and traditional Thracian houses, marking the end of the stage.
• Vineyard slopes — Kırklareli is part of a wine-growing belt, and the lower segments pass through vineyards that turn gold in autumn.

Best Time to Hike the ST604 Kirklareli - Üsküpdere

Thrace has a transitional climate — hot dry summers and cool damp winters — so the shoulder seasons are by far the most comfortable. The single best month is May: daytime temperatures sit pleasantly around 20–24 °C, the Istranca forest is in full leaf, wildflowers carpet the meadows, and the streams still run after spring rain. Late April and early June are nearly as good. As of 2026, regional forecasts continue to show May as the driest of the spring months with the longest stable weather windows.

September and October make a strong autumn alternative, when the vineyards colour and the heat of summer has broken; expect 18–25 °C and crisp, clear ridge views. Avoid July and August, when temperatures regularly exceed 33 °C and shade is limited on the open vineyard segments. Winter walking is possible but discouraged — the higher Istranca woods turn muddy and fog-bound from December to February, navigation becomes far harder, and daylight is short. Whatever month you choose, start early to bank daylight, since there is no overnight infrastructure mid-stage.

Practical Information

Accommodation

Kırklareli is the logical base before and after the walk. The city has a cluster of small hotels and guesthouses, with simple double rooms running roughly €25–45 per night and mid-range business hotels around €50–70. In Üsküpdere itself, formal accommodation is scarce; many walkers arrange a homestay or village room informally through the tea house, typically €15–25 including breakfast, or continue by minibus back to the city. Wild camping is tolerated in the forest belt but you must be discreet, carry out all waste and never light fires during the summer fire-risk season. A lightweight tent and stove are essential if you intend to sleep on the trail, as there are no staffed refuges anywhere on this stage.

Getting There & Back

The nearest major airport is Istanbul Airport (IST), roughly 230 km and a 3–3.5 hour drive to the southeast. From Istanbul's Esenler bus terminal, intercity coaches run to Kırklareli in about 3.5–4 hours. Kırklareli also sits near Edirne, about 60 km west, which has frequent bus connections. Local dolmuş minibuses link Kırklareli with surrounding villages including Üsküpdere; services are infrequent, so confirm return times before you set out. There is no passenger rail station in Kırklareli itself, making the bus network your most reliable option. Plan your fuel and food carefully — read up on how to estimate energy needs in our guide on how many calories you need hiking a full day.

Permits & Fees

No permit or entry fee is required to walk the ST604 — the Sultans Trail is a free public cultural route, and the Istranca forest tracks are open access. However, this is a sensitive border region close to Bulgaria, and military zones exist further north toward the frontier. Carry your passport at all times, stay on marked tracks, and do not photograph any military installations. If you plan to detour to Dupnisa Cave, a small entry fee of around €3–4 applies. Always check the latest official guidance from the trail authority before travelling, as access notes are updated each season.

Gear & Packing List

Because the ST604 is remote and self-reliant, your pack needs to carry everything for a full day — and a night, if you are camping. A comfortable 35–55 litre pack is the right size for this stage. The Abisko Hike 35 suits a fast day-walk with light camping gear, while a larger load is better carried in the Aether 65 if you are linking several Sultans Trail stages back to back. Ultralight hikers covering the whole Turkish leg often prefer a frameless option like the 2400 Windrider to keep weight down over long forest days.

Beyond the pack, prioritise: a GPS device or phone preloaded with the official GPX track and offline maps; at least 2–3 litres of water capacity plus a filter for the springs; sturdy trail shoes with grip for muddy woodland; sun protection for the exposed vineyard sections; a basic first-aid kit; and a paper backup of your route. If you are weighing up pack choices for a longer thru-hike of the trail, our roundup of the best ultralight backpacks of 2026 compares seven tested options. Track every item and its weight in the HikeLoad gear database so you know exactly what you are carrying before the start.

Similar Trails You Might Like

If the cultural depth and quiet remoteness of the Sultans Trail appeals, Turkey offers other long-distance routes with the same blend of history and landscape. The country's flagship waymarked trail is a natural next step for anyone drawn to multi-day walking with archaeological highlights and coastal scenery.

• Likya Yolu (Lycian Way) — Turkey's celebrated 540-km coastal trail along the Mediterranean, linking ancient Lycian ruins, pine forests and turquoise bays. Far busier than the ST604 but superbly waymarked and a rite of passage for thru-hikers.

For something further afield in the same expert-difficulty bracket, the cross-border alpine crossing covered in our guide to hiking the Theth to Valbona trail in Albania offers a comparable mix of remoteness and dramatic terrain.

Frequently Asked Questions

When is the best time to hike the ST604 Kirklareli–Üsküpdere?
May is the single best month, with daytime temperatures around 20–24 °C, a forest in full leaf and stable, dry weather. Late April, early June and the September–October window are also excellent. Avoid July and August, when heat above 33 °C makes the exposed vineyard sections punishing, and skip winter, when the forest turns muddy and fog-bound.

How difficult is this stage?
It is rated expert, but the challenge is navigational rather than physical. Total climbing is only around 500 metres over roughly 18 kilometres. Waymarking thins out in the Istranca forest, mobile coverage is patchy, and there are no refuges, so you must be confident with a GPS track, carry your own water and food, and be self-reliant throughout the day.

How many kilometres should I plan per day?
The ST604 is designed as a single walking day of roughly 18 kilometres between Kırklareli and Üsküpdere. Most fit hikers complete it in 6–7 hours including breaks. If you are linking it with neighbouring Sultans Trail stages, plan 15–22 km per day across this Thracian section, starting early to make the most of daylight and reach a settlement before dusk.

Where can I sleep on or near the trail?
Kırklareli has hotels and guesthouses from about €25 per night, making it the best base. Üsküpdere has only informal village rooms or homestays, usually €15–25 with breakfast, arranged through the local tea house. There are no staffed huts mid-stage, so wild camping with a lightweight tent is the only on-trail option — discreetly, with no fires in summer.

Do I need a permit or fee to walk it?
No permit or fee is required; the Sultans Trail is a free public cultural route and the forest tracks are open access. Carry your passport, as this is a border region near Bulgaria with restricted military zones to the north. Stay on marked tracks and avoid photographing any military sites. The optional Dupnisa Cave detour charges a small entry fee of around €3–4.

For official route information, GPX downloads and the latest access notes, consult the Sultans Trail organisation, and check broader country guidance with the official Türkiye tourism authority before you travel.