Sailors in the Gulf of Finland used to say that Kotlin Island was a long grey shape you saw only when you were already too close, and Southern Battery No. 3 is part of the reason the sailors came to respect it. It stands on the low, southern shore of the island, facing the channel that runs past Lomonosov on the mainland, one of a numbered line of coastal batteries that guarded the approach to Saint Petersburg from the sea. The batteries were built for guns and are now mostly quiet, grassy ruins of earth, brick and concrete.
The dam changed everything. Until the early twenty-first century the island was reachable only by water, which is why its fortifications stayed so well preserved, and then a long flood barrier was built across the gulf, with a road along the top. That road now links the island to the mainland on both sides, and a ride out here begins with a long, flat, windy run beside open water and the grey shapes of ships waiting for the port. In a strong westerly the bike will be pushed around, and in winter the surface can be glazed. The sea smells of salt and diesel.
On the island itself the roads are straight, flat and sometimes broken, and the area around the batteries is an odd mixture of military land, birch scrub and old earthworks. Photography near active military sites can cause trouble, and it is worth asking before you point a camera at anything with a fence round it.
For fuel, rely on Kronstadt, which has over forty thousand people and a full range of shops. Cafes in the town are plain but warm, and the portions are generous. Lomonosov, on the mainland side, has a similar population and is the better place to stop if you are coming from the south.
The white nights of June make the long evening light on the water remarkable, and the island is quiet then. In autumn the weather turns fast, with fog and rain, and the long run on the dam can be unpleasant. Dress for the sea, not for the city.