In the centre of Reykjavík there lies a grassy hill called Öskjuhlíð. Unusually for Iceland, Öskjuhlíð sports a thick covering of greenery, so you can pick one of its many winding paths and enjoy a walk through the pine woods. At the top of the hill is Perlan—one of Reykjavík’s landmark buildings—a shining glass dome set on six huge water tanks. It’s a futuristic piece of architecture that bears checking out, but if you head west from there, you might find some history instead. Nestled amongst the trees is a smattering of war relics left by the British when Öskjuhlíð functioned as a defence post during WWII. You can peek out from the pillboxes, stroll through the dilapidated control centre and venture into the gloomy bunkers. The structures are looking a little worse for wear, and the bunkers are now used more for graffiti-ing and partying instead of fending off Germans, but these crumbling remains still provide an eerie reminder of a time gone by.