Why Vilnius for a city break?
Vilnius has the largest baroque old town in Northern Europe — a UNESCO World Heritage Site of 1,500 buildings from the 14th to 18th centuries, spanning Gothic, Renaissance, Baroque and Neoclassical styles in a labyrinth of lanes that rewards aimless wandering more than any other Baltic city. It also contains Užupis: a self-declared independent republic within the city, founded by artists in 1997, with its own constitution (which includes the right to be idle and the right to be a cat), its own president, its own currency and its own flag. Genuinely, magnificently bizarre.
From London it's three hours — direct flights from Heathrow and Gatwick, with good connections from regional airports. Vilnius Airport is 7km from the centre (train €0.72, 7 minutes — one of the best airport connections in Europe). The city is extraordinary value: a complete dinner with drinks costs under £15, a craft beer is under £2, and hotels are a fraction of Tallinn or Riga prices. Go in May to September; December brings the finest Christmas market in the Baltic states. The Jewish heritage of Vilnius — once called "the Jerusalem of Lithuania" — is among the most important and most devastatingly complete in Europe.