Arambol Beach is one of the most beautiful and peaceful beaches in Goa I've visited. Clear blue waters, rocky cliffs, good eateries- this place has it all. If you visit Arambol, do not miss out on the Sweet Water Lake. It's a small lake which is about a half hour walk from the main beach (It's nestled behind the rocks and the walk takes you through a lovely little market; also there are a number of cafes here with breathtaking views of the sea).
A swim in the Sweet lake and chilling on that section of the beach can be hugely rejuvenating and the place is very peaceful, guaranteed to give you good vibes. There's also a small hike to a hill overlooking the sweet lake that I'd recommend.
PS. There is no network coverage in the sweet lake area.