Lonely Planet review
Naissaar, at 44 sq km, has a lively history, thick forests (covering 85% of the island), and even a boulder with a circumference of nearly 27m! There's a 19th-century cemetery for English sailors from the Crimean and Russo-Swedish wars, which attests to the island's military history.
In fact, Naissaar has been a bulwark for defending the capital since the Great Northern War. A railway was even built before WWI for a speedier build-up of armaments. Curiously, from 1917 to 1918, tsarist troops took the island and tried to form their own government. Soviet military traces remain (the island was closed until 1995), with an old army village, gun batteries, empty mines and deep-sea mine anchors. There are dreamy stretches of unblemished beach and two nature trails: south takes you to historical sights, such as memorials, military ruins, a wooden church from 1856, a cemetery for English sailors from the Crimean (1854-55) and Russo-Swedish (1808-09) wars; north leads through forests, mires and past large 'erratic' boulders. Just up the hill from the dock is the Nature Park Centre where you can get lots of info, a warming coffee and a meal.
There are several affordable accommodation options on the island during summer months.
To get there, MS Monika departs from Tallinn's Linnahall Terminal, twice daily on Saturdays and Sundays only during summertime. If you're day-tripping, you'll have five hours on the island.