The main road running down the Turkish Black Sea coast is the D010, and it is this road that we more or less followed (and will be following) all the way. The coast is known to be wet and rainy in winter, and this is exactly the weather we had on our first few days cycling down the coast. We arrived in Karasu, the first town we reached on the coast, in the pouring rain, and it continued raining on and off all the way to Ereğli. We were literally under the weather and were falling sick by the time we reached Ereğli, and we ended up staying 3 nights in this small town with our Warmshowers host.
The road to Ereğli was more or less flat, but after Ereğli was where the mountains started. From Ereğli to Zonguldak and then to Çaycuma, the road went inland and up to altitudes of 400-500m at times, and this was where we saw snow - lots and lots of it. We were cycling in a winter wonderland! This section of road (like everything before it) has also been upgraded to a 4-lane highway with plenty of tunnels, and we speculate that this is why the road runs inland here, instead of hugging the coast (as it does later).
From Çaycuma, we followed a surprisingly flat road in a wide valley to Bartın. From Bartın, it was back onto mountainous roads that led back to the coast near Amasra, a picturesque town built on a peninsula and two small islands in the Black Sea. We did not go down to Amasra itself, however, as it was a 200m descent from the main road (i.e. 200m ascent back up).
Having cycled on a 4-lane highway all the way to this point, we expected it to stay this way, having heard and read similar (but, as we now know, incomplete) reports from others about the D010. However, shortly after Amasra, the new D010 ended abruptly and merged with the old D010, a small road that winds up and down and in and out of all the mountains on the coast. From some parts of the road soon after we branched off, we could see the new D010 under construction, always emerging from some tunnel in the mountains. The old road is definitely tougher to cycle, but also much more scenic, hugging the coast more than the big road ever will.
The section from Bartın to İnebolu is the most mountainous section of the D010, and we planned our days to keep our climbs to less than 1000m per day. This resulted in several days when we covered only about 40km or even less. This, combined with the relative remoteness of the region, meant that we had to camp more often, as we did not cycle far enough in a day to reach towns big enough to find hosts or paid accommodation. Thankfully, the weather changed for the better, with no more rain or snow, some days of sun, and much warmer temperatures, rising to (and even above) 15°C on some days. Perfect weather for camping on the many small beaches on the coast!
Unfortunately, Hannah fell sick in İnebolu, and we took the next few days even more slowly. Thankfully, İnebolu itself and the few towns after that are bigger, and we managed to find hotels for four nights in a row while Hannah recovered. The section from İnebolu to Sinop is also less mountainous than the road before, and we saw even more sections of the new D010 road under construction.
Sinop is a city on a peninsula more or less in the middle of Turkey's Black Sea coastline, and the northernmost point of the country. Additionally, after this point (or more precisely, after Gerze, the next town after Sinop), the road is almost flat. This makes Sinop a logical point to conclude Part 1 of our ride along this coast.