Trakai is a town in Lithuania, located approximately 20 km west of Vilnius.
By train or by bus from Vilnius. It takes about 30 to 45 minutes. Tickets for the bus can be purchased at the bus station in Vilnius and cost about 5,60 Litas (one way).
The town is small enough for everything to be reached on foot, but there are also buses running from the bus station (where the buses from Vilnius also arrive/depart) to the castle.
Alongside the lake with the castle, there is a small boulevard with many kiosks. You can buy a wide range of souvenirs here, ranging from booklets to authentic Soviet military headware.