Short answer: From Penzance bus station, buses to Marazion Square take 12–15 minutes and run regularly; or walk the flat coast path beside the railway for about an hour. Marazion Square is a five-minute walk from the causeway.
Marazion is three miles from Penzance station, and on a summer day arriving without a car is not a compromise — it's the easier option.
Buses leave from Penzance bus station, which is next to the railway station, and take around 12 to 15 minutes to Marazion. Several routes serve the town (the U4, 2 and 15 have all done so; check the Transport for Cornwall journey planner for today's timetable). Get off at Marazion Square — from there it's a five-minute walk down to the beach and Chapel Rock, where the causeway starts. If you're heading straight for the Mount, the stop before the Square, by the long-stay car park, is slightly closer to the beach.
The South West Coast Path runs from just outside Penzance station along the top of the beach, beside the railway line, all the way to Marazion. It's flat, mostly tarmac or firm path, and takes about an hour at an easy pace with the Mount growing in front of you the whole way — genuinely one of the better hours in west Cornwall. It's pushchair-friendly and there's a café halfway at Jordan's Cafe by Long Rock. Do it there, bus back if legs are tired.
Same path, 15 minutes. Bike racks are in the car park next to The Godolphin, Marazion.
The point of coming without a car is flexibility, so use it: check the causeway calculator, and if the walking window is in the afternoon, do Penzance in the morning and stroll along the bay to arrive as the cobbles clear. If it's a boat day, the boats land at one of three points along the beach depending on the tide, and staff direct you.
Evening buses thin out, so check the last one before settling into a second pint at The Kings Arms. Taxis from Penzance are easy to book and it's a ten-minute ride.
See the full Marazion guide, filtered by who's with you.
Plan your day near Marazion →