3718 SANDSPUR Lane At the water's edge of Sandspur Lane sits one of Casey Key's best-kept secrets: a stunning estate offering unmatched privacy, tranquility, protected waterfront, and bespoke contemporary coastal architecture. A multi-year renovation completed in 2024 reimagined the property, adding more than 2, 000 square feet of interior and exterior living space and transforming an already exceptional waterfront home into a truly distinctive residence. Tucked at the end of this quiet, private lane, the home's structural features and sheltered location provide proven storm-resilient advantages. Ownership of both sides of the canal protects the mature trees and vegetation along the opposite shoreline, preserving natural privacy. The main level features vaulted ceilings and an open floor plan connecting the modern kitchen with dining, living, and family rooms, while wraparound aquarium glass windows and sliding glass doors flood the space with natural light and offer views of the water and the parcel's expansive waterfront setting. A floating staircase rises through a circular glass stair tower to the primary suite, featuring a spacious bath, sitting room, and a private balcony with long water views. An adjoining casita with its own private entrance and water views provides luxurious accommodations for family, guests, or in-home staff. Two dedicated offices with built-in cabinetry and granite desks offer long ICW views, creating an inspiring setting for work or personal pursuits. A new elevator connects every level, from the garage to the rooftop deck. Designed for recreation and entertaining, the property features a cabana with bar and outdoor kitchen, a new waterfall spa and remodeled pool with water features, a home gym, firepit, indoor-outdoor Sonos sound system, and multiple balconies, terraces, and decks. After sunset the extensive outdoor lighting, including dock and underwater fish lights, transforms the property. The long driveway and motor court accommodate parking for 12-15 vehicles- a rarity on Casey Key. The 200 feet of protected waterfront includes a newly added 45-foot dock, 20, 000-lb. boat lift, and two PWC lifts. And when the Gulf beckons, deeded beach access leads to its warm waters and shoreline. From sunrises over the ICW to Gulf sunsets from the rooftop deck and illuminated evenings poolside, the home embraces its waterfront setting from virtually every angle. This residence offers a package increasingly hard to find: extraordinary privacy, tranquility, and protected waterfront living-all wrapped in a beautifully reimagined contemporary coastal estate on one of Florida's most exclusive islands.