Tucked away in a leafy canyon across the street from Hotel Bel-Air is the first security gate. The Park Bel-Air, among the most prestigious new boutique developments in the United States, begins here. Behind the gate, the road turns uphill and splits three ways, leading to three more eventual security gates. No one knows yet exactly what will come next.

The ultraprime developer Domvs London has secured permits to build three massive residences on the three hilltop lots, boasting panoramic views over Bel-Air and west to Santa Monica and the Pacific Ocean. Interested parties can buy a lot, no strings attached, or work with Domvs to customize existing permitted house plans. Domvs promises that with the latter option, owners will move into their new homes in just 24 months.

Consider estate No. 2: The 3-acre lot can be purchased for $45 million, or both land and home can be purchased starting at $115 million, depending on final specifications. The main home measures up to 43,000 square feet, the guesthouse up to 16,000. Existing plans include amenities like an in-home IMAX theater; golfing and racing simulators; a spa with treatment areas, saunas, and steam rooms; a bowling alley; and both main and service elevators. Domvs secured permits for maximum-sized homes, allowing clients with more modest wishes to easily reduce the specs.

Pricing for estate No. 1 comprising 3 acres with a 58,000-square-foot home and estate No. 3 comprising 4.5-acres with a 66,000-square-foot home will be released next year. (Inquiries: Westside Estate Agency, Kurt Rappaport, 310.860.8889; weahomes.com)