The New York cityscape contains an amalgam of architectural styles. Behind the closed doors of the city’s penthouses and brownstones, there’s an even more fascinating array of design details.

Every October, Open House New York gives locals and visitors alike the chance to peep in on sites that are usually exclusive: from preserved historical buildings to contemporary apartments, from landmarks to industrial structures. Across all five boroughs, architecture and urban design masterpieces will go from off-limits to accessible between October 18-20.

When those doors open to the public, you’ll have the opportunity to learn through tours and talks with architects, urban designers, historians, preservationists, and city leaders.

If you can’t catch the Open House weekend, you can always open for a year-round architectural tour through any of Manhattan’s distinct neighborhoods. Lex Hotel is within easy walking distance to the Flatiron Building and Gramercy Park, so architectural and urban design gems abound.