There are easily accessible roman ruins and a museum quite near downtown and just a stone's throw from Lake Geneva.

The Musée Romain de Lausanne-Vidy with archeological park explains the Roman history of Lousonna on Lake Geneva.  Roman settlement dating back to around 15 B.C. on a site occupied since the Mesolithic era. Its population of 2’000 began to vacate the site in the 4th century when migrating to the Cité (old town).

What is truly amazing is that the runis are just out in the open, you can walk in and out of the rooms, over the walls, and really imagine what the settlement might have looked like.