Porta Marina

You're at Porta Marina, the Sea Gate. It's named for the view. In Roman times the coastline was much closer than it is now, and from up here you could watch boats coming in at the mouth of the river Sarno, where Pompeii had its harbour.

Look at the two vaulted passages. The narrow one was for people on foot, the wider one for pack animals. No cart could handle this slope, because Pompeii sits on an old lava flow, high above the plain. Its walls ran for more than three kilometres, with seven gates that we know of.

Underfoot, the street is paved with big blocks of grey lava, cut into irregular shapes and fitted together like a jigsaw. You'll walk on stones like these all day. Further in, you'll find deep ruts worn by cart wheels and raised stepping stones for crossing the road.

Just inside the gate, on your right, stood the Temple of Venus, the town's patron goddess. Its terrace faced the sea, so it was the first thing sailors saw. Today, little survives above the foundations.

Carry on uphill along Via Marina. The Basilica is on your right, just before the street opens into the Forum.