High up in the hills to the northeast of the city sits an ancient Iron Age village that most locals don't even know exists. Inhabited between the 6th and 2nd centuries BC, it was thought to be one of the most important settlements in the area because of its size – roughly 4000 sq metres. Today much of it still remains, and visitors can walk its ancient rocky streets and explore the remnants of old dwellings.
It's a tough hike to get there, but you'll be rewarded with magnificent views, all the way down to the sea. From the centre, the best way to get there is to take metro L1 to Santa Coloma and then either buses B14, B80 or B81 to stop Can Franquesa-Menorca. From here, it's a good 40-minute hike up the gravel Carrer Camí Vell a Montcada or the steep footpath known as the Camí a la Font del Torrernt de les Bruixes.