Key Biscayne offers a variety of attractions and activities that showcase its natural beauty and local culture. Here are some popular sightseeing places and things to do on Key Biscayne:

1. Bill Baggs Cape Florida State Park: Located at the southern tip of Key Biscayne, this park is home to the historic Cape Florida Lighthouse, which offers panoramic views of Biscayne Bay and the Atlantic Ocean. Visitors can tour the lighthouse and explore the park's trails, beaches, and picnic areas.

2. Crandon Park: A large urban park on Key Biscayne featuring a beautiful beach, picnic areas, and nature trails. It's a great spot for swimming, sunbathing, kayaking, and paddleboarding. The park also has a marina and the Crandon Park Tennis Center, host to the Miami Open tennis tournament.

3. Crandon Park Marina: A full-service marina offering boat rentals, fishing charters, and waterfront dining options. It's a hub for boating enthusiasts and provides access to nearby islands and fishing spots.

4. Key Biscayne Heritage Trail: A self-guided walking or biking trail that explores the island's history and natural environment. The trail includes points of interest such as the Cape Florida Lighthouse, the Miami Marine Stadium, and the Crandon Park Gardens.

5. Miami Seaquarium: Located near the entrance to Key Biscayne, this popular marine park features dolphin, sea lion, and killer whale shows, as well as exhibits showcasing marine life native to South Florida.

6. Biscayne Nature Center: A non-profit organization dedicated to environmental education and conservation. They offer guided tours, educational programs, and hands-on activities focused on the local ecosystems and wildlife of Biscayne Bay.

7. Historic Virginia Key Beach Park: Just across the Rickenbacker Causeway from Key Biscayne, this park is home to the Historic Virginia Key Beach, a former segregated beach that is now a designated historic site. It offers beach access, picnic areas, and scenic views of downtown Miami.

8. Sailing and Water Sports: Key Biscayne's location makes it an ideal destination for sailing, windsurfing, kiteboarding, and other water sports. Many local companies offer rentals and lessons for visitors of all skill levels.

9. Local Dining and Shopping: Key Biscayne has a variety of dining options ranging from casual beachfront cafes to upscale restaurants serving fresh seafood and international cuisine. The island also has boutique shops and galleries showcasing local art and crafts.

10. Miami skyline views: From various points on Key Biscayne, especially along the Rickenbacker Causeway or from the parks and beaches, you can enjoy stunning views of the Miami skyline and the surrounding waters.

These attractions and activities make Key Biscayne a popular destination for both tourists and locals seeking outdoor recreation, natural beauty, and cultural experiences just minutes from downtown Miami.