Kharkiv has one of the three metro systems in Ukraine (along with Kyiv and Dnipro), and several of its stations are worth seeking out for their Soviet-era interior design. The system covers the city well and is the fastest way to move between the city centre, the university district, and outlying areas.
The most visually striking station is Istorychnyi Muzei (Historical Museum) on the Saltivska Line, which features enormous mosaic panels depicting scenes from Ukrainian history — Cossack battles, the founding of Kharkiv, industrialisation — in a Socialist Realist style of considerable technical accomplishment. Maidan Konstytutsii station in the city centre has a spacious hall with marble columns. Even if you are not travelling by metro, buying a token and descending to the platform level of Istorychnyi Muzei is worthwhile for a few minutes.