In reply to the.last.thesaurus:
There are some bits of climbing, such as Montis in Vilnius and The Rock in Kaunas. Bouldering here too: . Might be worth getting in touch with those guys.
Lithuania is fairly flat. Rock is sparse as well, Puntukas (
https://en.wikipedia.org/wiki/Puntukas ) being the largest in the country. Chipped as well! You'd be better off going to Southern Poland/Czech Republic/Slovakia/Romania if you really wanted to get some climbing/mountains. Not for a day trip, obviously...
On the other hand, it would be ashame to miss out the Curonian Spit and wonderful forests all around the country. Lakes around Zarasai and Moletai are quite nice as well.
I grew up in Lithuania, but Scotland is my home now. That's where I picked up most of my mountain activities.
PM me if you need some assistance. I have been home only for around 3 weeks in total over last 5 (nearly) years, so I am sure lots of things have changed.