This is a paid asset, but now you can download Beach Assets Free.
Detail this asset from Unity Store: Original Link
Beach Assets v1.0
“If possible, please buy the package to support the developer”
Beach assets low poly models with proper texture. It is very useful for games. I already created a sample test scene with proper light mapping.
Create your own beach sitting area using this assets package.
The package contains:
Hut and Trees
water and sand sample planes
Assets poly count 15000 Tris
Every asset included has a prefab set up for you. You can create your own beach area using this assets package.