Riga's evenings run at a different pace than its daytime sightseeing. Old Town keeps its cobbled streets lit long after the House of the Blackheads closes, and the same district covered in the main Riga travel guide fills up again after dark for a slower kind of visit.
The evening ghost walks and cemetery tours already covered in that guide's ghost walks and cemetery walk pages are one way to spend a night out. Bars, Black Balsam, and Latvia's licensed real-money gambling scene are the others, and each is worth knowing before booking anything.