Portland Cottage is in Mousehole, right near the harbour. It's a semi-detached place, traditional inside. It's a family home, so it's comfortable but not modern. It sleeps six, with three bedrooms and two bathrooms. It's got a 3 Star rating. The main thing is there's private parking, which is quite rare here.
The stairs inside are steep. They're original cottage stairs. There's a stairgate at the top if you need it.
You're about fifty yards from the little beach and the harbour. The village shops, the pub, and a couple of places to eat are a few minutes' walk. It's a proper old fishing village, so the streets are narrow and it's busy in summer. The Christmas lights are famous. They were started by the previous owner's father.
For a bigger beach, you drive to Marazion. It's about ten minutes. You can see St Michael's Mount from there. It's a National Trust site you can walk to at low tide, or get a boat over. The National Trust St Michael's Mount page has the visiting times.
Penzance is a five or ten minute drive. There's a railway station there if you don't want to drive. Newlyn, the next harbour along, is even closer and has the art gallery.
The cottage has a washing machine, a dishwasher, wifi, and an enclosed patio garden. It's fine for one well-behaved dog. Bedding and towels are included.
If you're planning trips, the National Trust Cornwall site is useful, and so is Cornwall Council's beaches page for practical info.