Museum HQ near the main street, in a former Dominican Monastery, near Peninsula Castle. The museum has several affiliates. The Island Castle, a reconstructed residence of Lithuanian dukes in 14th century, is the most famous castle in Lithuania, probably a symbol of medieval Lithuania itself. Many concerts and plays in summer.
The kenesa (synagogue) of the local Karaite community.
By train or by bus from Vilnius. It takes about 30 to 45 minutes. Trains depart Vilnius a only few times a day, so make sure you plan accordingly. The last train to Vilnius from Trakai departs at 21:30. Tickets for the bus can be purchased at the bus station (from the driver) in Vilnius and cost about €2 (one way). The buses may be late, or not come as often as the posted schedules, especially in the evening.
From the bus station, it's a 15-20-min (3-km) walk to the castle, about 10 min longer if you're coming from the train station.
Trakai is located along Lithuanian road A16 (part of European Route E28) and therefore easily accessible by car. Parking is a pain though, but you can park for free at the Free parking lot at the end of Varnikai villageFrom this parking lot, you it is about 1 km to the castle.
More information available on Wikivoyage
No climate information is available for this destination.