Sampson Cathedral is one of St Petersburg's older churches, founded after Peter the Great's victory at Poltava in 1709 and later rebuilt in stone. Its history is tied closely to the early imperial city and to Russia's long memory of the Northern War.
The cathedral is away from the main palace-and-museum circuit, so it is best for travellers with time to explore north of the centre. The monument-museum setting gives more context than a quick exterior stop.