Baku Flame Towers Project, consisting of three high-rise towers, a shopping mall and an underground car park is being constructed in Baku, Azerbaijan. The project site is located on the city center neighboring two major boulevards, and some important buildings such as National Assembly of Azerbaijan, General Staff Building and Central Clinic Hospital. The soil profile at the site generally consists of a fill layer and slope debris with varying thicknesses from the ground surface, and very stiff – hard clayey silt underlying the fill layer. Below the silt layer, a poorly cemented sedimentary rock layer with a poor rock quality is encountered. Due to the inclined topography of the project site, excavation slopes with depths varying between 2.0m and 29.0m have been foreseen in accordance with the architectural design. In order to carry out the foundation excavation safely an earth retaining structure consisting of bored piles tied-back by temporary ground anchors has been designed and constructed successfully. The retaining system constructed within Baku Flame Towers Project has the distinction to support the deepest foundation excavation ever made in Baku, Azerbaijan. Due to high structural loads, tower buildings have been designed to rest on raft foundations with large diameter piles. Bored piles with a diameter of D=1.20m and length of L=36.0m have been designed in accordance with the required load capacities, and anticipated pile capacities have been proved successfully with pile loading tests performed by using Osterberg Cells.