The tower was built in 1998 for the Expo '98 World's Fair.[4] At the base of the tower was a three-story building that served as the European Union Pavilion during the Expo.
The base of the building was to be leased for office space after the closing of the Expo, but never found tenants. Instead, it was used for one-off events, like the world premiere of the new Mini car in 2001.
Both the observation deck and the restaurant were closed in October 2004.
Parque Expo received permission to expand along the riverside in order to build a 20-floor, 178-room luxury hotel, a plan by Portuguese architect Nuno Leónidas.[5] The base of the tower was demolished between July and September 2007, paving the way for the construction of the 5-star Myriad hotel, which opened in 2012. In 2018, the panoramic restaurant Fifty Seconds (by Martín Berasategui) opened in the space that was previously the observation deck. Within a year, it received its first Michelin star.
The architects were inspired by the form of a caravel and its sail, supported by fundamental volumes at its base.[4] This base, enters the river like the bow of the boat, supported by pillars forming a terrace.[4] This area is occupied by exposition spaces and vestibule with access to panoramic elevators that intersperse the tower to the restaurant and viewing platform.[4] The tower is defined by a vertical "mast" and a metallic, tubular "sail", surmounted by a 120-metre (390 ft) platform forming a "crow's nest", corresponding to the rotating restaurant and visitors viewing area.[4]