Excavations and observations on adjacent sites in the heart of London's ancient harbour produced exceptional evidence of waterfront activity from the mid-first into the fifth centuries. To the south of the natural pre-urban river bank were found substantial traces of structures thought to represent a pier base for a timber bridge across the Thames and an open-work landing-stage. The latter was replaced in the late first century by an infilled timber-faced quay traced for over 70 m east–west. Two storage buildings, each 25 m × 6 m, were laid out over the northern half of the quay area. The line of the waterfront had been advanced beyond the southern limit of excavation by the early second century, and again by the early third century, and these major modifications are reflected in the subsequent development and layout of the buildings and associated features recorded in the excavations.The well-preserved timber structures are described and illustrated, the development of the storage buildings is discussed in detail, and the first century river level is assessed.