If you love looking down from high up you could do that even in lowland Lithuania. Masts and towers have been constructed where there are no hills. Moreover, most of the best vantage points are free of charge. Here are our suggestions:
1. St. John's belfry is the tallest building in Vilnius Old Town (68 m) and a recent renovation ensured that it may be easily ascended by an elevator (summer only). The breathtaking views from here are the best in Vilnius as you will be located right in the middle of one of the Europe's largest medieval towns.
2. The 52 m tall Parnidis sand dune near Nida seems to be an end of a civilization in more than a single way. After an easy short hike to the top and looking southwards you will see neverending dunes and forests (known as the Lithuanian Sahara). They are squeezed from both sides by massive waters - Baltic Sea and the Curonian lagoon. And Parnidis dune is also the end of Lithuania, the end of European Union, the end of NATO and Catholic world as much of what you will see will be in Russia.
3. Kaunas is definitely at its best when looking from the Aleksotas vantage point, its gothic churches proudly rising above the Hanseatic old town. It is arguably the best urban vantage point in Lithuania. Free of charge, no climbing needed.
4. The classic Lithuanian nature of lakes and forests is at its best at the 36 m Lake Sartai observation mast (Baršėnai village), guyed and trembling in the wind. The long and narrow lake and its islands are one of the Lithuania's prettiest natural panoramas. Free of charge, no elevator.
5. Druskininkai cable car is the only one in Lithuania and offers great views of the canopy of lush Dzūkija forests and Nemunas river with its island. Unlike most cable cars, this one was built on lowland terrain precisely to offer the views, rather than to access high altitude locations.
6. Gediminas hill castle tower views are the most popular in Vilnius and are especially variable as Old Town is visible on one side while new districts are on the other. You will be standing near the Lithuania's prime flag - the first thing every modern conqueror of Vilnius was masting his flag there. WW2 guerillas would have risked their lives to secretly host their flag on the tower and they witnessed the same view of the city as you would. These days the frail may ascend the castle hill using a lift.
7. The views from the Three Crosses Hill in Vilnius Old Town may be similar to that from the Gediminas Castle hill with one important exception: you may see the castle tower itself and Vilnius skyline is never complete without this red-brick city symbol.
8. Whatever high the observation masts, towers and hills would be nothing can be the same as actually silently raising above the ground in a hot air balloon. With one of the world's highest numbers of balloons per capita and balloon-friendly laws Lithuania is certainly a great place for that. Every summer morning and evening a group of balloons rises above Vilnius and many other places, and you may book your place in one of them.
9. Vilnius TV Tower is the nation's tallest building (326 m) and while its observation deck is lower (165 m) it's still the highest in Lithuania. That said, the views from there lag behind places in the Old Town as the TV Tower is located in blunt Soviet districts. The entire observation deck is an overpriced revolving restaurant and the ascension prices make it the Lithuania's most expensive fixed vantage point (arguably also a tourist trap).
10. Palanga Sea Bridge may be not that high above sea level (only ~5 m in fact) but it has captured romantic feelings and imagination of some 6 generations. Constructed as a "bridge" that goes into the sea and ends at ~470 m it replaced an original wooden predecessor (built 1882). Strolling to the end of the bridge is a must for any visitor of Palanga resort and it is best enjoyed with one's loved one during sunset when the sun settles down into the Baltic Sea. Alternatively, you may try to witness the fury of the storms when the waves could even splash you if you are standing on the lower platform. Looking towards the continent you may see sea shores all the way up to Latvia. Free of charge.