Cullen Center is a skyscraper complex in Downtown Houston, Texas, United States.

In 1959, the family of Hugh Roy Cullen, an oil businessperson and philanthropist who was recently deceased, announced that they would build a skyscraper complex in Downtown Houston.

[3] During the year, the family's plans also included another 25 story office building and a parking garage.

Gerald E. Veltmann, the president of Cullen Center, Inc. said that the development "represents a marked departure from the traditional downtown scene and colors" because the development "centers around a planning concept with four separate levels structures: sub surface, used for parking and mechanical equipment; surface, used for vehicular traffic, parking, entrance lobbies, and service entrances, a second level, used for pedestrian-oriented facilities such as main lobbies, shops, displays, galleries, lounges, and restaurants; and the top space, into which will rise the main towers containing hotel rooms and offices.

[10] By 1987, the Canadian company Trizec Corporation bought debentures carrying an option to buy portions of the Cullen Center, including 1600 Smith Street.

[13] Tim Reylea, the vice president of Cushman Realty Corp., said that the Continental move "is probably the largest corporate relocation in the central business district of Houston ever.

[15] In 2008, Continental signed five-year lease renewals for its Downtown Houston office space.

[16] 500 Jefferson, with its construction scheduled to begin on October 1, 1960, was the first building in Cullen Center to be developed.

[19] In 2004, the law firm Lapin & Landa LLP signed a lease agreement to occupy 7,922 square feet (736.0 m2) of space.

Paul Layne, Brookfield's Houston area executive vice president, said that the KBR lease made the building a major candidate for sale.

[22] 1801 Smith, previously Continental Center II, then 600 Jefferson, has 20 stories and 449,087 square feet (41,721.5 m2).

[29] In November 2014, Brookfield sold the building to DRA Advisors and Stream Realty Partners.

[22] In addition to millions of dollars of renovations and upgrades, the property address was permanently changed in March 2017, to 1801 Smith Street, Houston, TX 77002.