Around 800 British troops from 5 RIFLES have deployed to Estonia for a six-month tour.
They’ll be part of NATO’s Enhanced Forward Presence, which will have 4,000 troops stationed across the region, including French and Danish soldiers.
Captain Jack Lister described the challenge this way:
"You've got 60 percent woodland - and it's dense forest - and six percent swamps. You cringe at the term, don't you, but for an armoured battlegroup, it's very different. Very congested, cluttered terrain, and it'll just be something that we need to get stuck into, basically."
British Armour is headed to Estonia too, in the biggest move of its kind since the end of the cold war.
5 RIFLES will be based in the small town of Tapa, where the existing barracks are being upgraded for their stay.
The renovation has upgraded or added classrooms, saunas, and welfare rooms as well as sleeping quarters:
When three years ago Russia annexed Crimea and put its troops in Eastern Ukraine, NATO rapidly decided to send troops and weaponry.
With the Russian border just 80 miles from Tapa, the British deployment sends a message that NATO is strengthening its eastern flank.