The Arecibo Radiotelescope is member of VLBI, and it is the largest radio antenna in the world, with a dish of 305 meter in diamter. The Arecibo Radiotelescope is built into a natural limestone bowl. Suspended 140 meters above the dish is the platform carrying the secondary antennas. Although the dish is too large to be moved, it can be pointed as much as 20° by moving the line feeds to the antenna's focus.