Basilica Sancti Petri or St. Peter's Basilica seen from across the River Tiber. Construction of the current basilica was undertaken between 1506 and 1626 replacing the original St. Peter's Basilica dating to imperial Roman times in the 4th century AD. The famous dome was completed in 1590, based predominantly on Michelangelo’s re-design of the original basilica plans. It rises 136.57 metres (448.1 ft) from the floor to the top of the external cross making it the tallest of its kind in the world. The Basilica is traditionally held by Catholics as the burial site of St. Peter, one of Christ's Apostles and also the first Pope, with his tomb said to be directly below the high altar of the Basilica. The Basilica lies within the small state of the Vatican City which is the independent Papal enclave within the city of Rome, Italy.