If you're spending some time in Matecumbe, Bud n' Mary's Dive Center and Anne's Beach are top sights worth seeing.
Though Lower Matecumbe Beach might not have many top sights, you can venture to the surrounding area to see attractions like Anne's Beach and Sunset Drive Beach.
If you're looking for some top things to see and do in Seabreeze Trailer Park and surrounding area, you can visit Founders Park and Islamorada County Park.