This is Pip's Cottage in Madron. It's a stone cottage, built from the local granite. It's on the edge of the village, quiet. You can see St Michael's Mount from the main bedroom window, over the rooftops.
It sleeps three. Two bedrooms and one bathroom. It's got a 4 Star rating, so it's comfortable and well looked after. I should mention the stairs. They're quite steep and narrow, like a lot of old cottages here.
You can bring one well-behaved dog. There's a small patio garden out the back. Bedding and towels are all provided, and there's a TV. The village pub is a short walk away.
You're just outside Penzance, so you can walk down into town or get the bus from the end of the lane. Newlyn and Mousehole are very close, proper working harbours. The coast path is right there for walking.
Within about twenty minutes drive you've got lots of the old sites. The Men-an-Tol stone, Lanyon Quoit, the Madron Well. The National Trust Cornwall page is good for planning that. For the wider area, Cornwall National Landscape has maps and ideas.
If you want a beach, Porthcurno or Sennen Cove are the nearest big ones, about a fifteen to twenty minute drive. Marazion is closer.