The present volume is the fifth publication of a Frontinus-conference edited by Gilbert Wiplinger as a BABESCH supplement volume on historical water science. At the place of activity of Sextus Iulius Frontinus as curator aquarum and the capital of the Roman Empire it was probably one of the most important and challenging events of this congress series. For the first time a new path was taken, as the organizer and publisher wanted to approach the topic water from the artistic side. This was realized in the opening lecture with the presentation of a novel in which Frontinus plays the main character and a photo exhibition at the Austrian Historical Institute about the integration of the Aqua Claudia and the Aqua Anio Novus in the new building of the waterworks of Limburg (Holland). In eight sections 33 contributions are published in this volume. The first section deals with the different approaches to the topic of water. The second section is dedicated to the award of the Frontinus Medal to Hubertus Manderscheid, who was honoured during the conference for his fundamental research on the history of ancient water supply over many decades. The third section is dedicated to the aqueducts of Rome. After a general introduction, Colle Papese in Tivoli, the Aqua Alsietina and the distribution of the Aqua Claudia and Anio Novus within the city were discussed. The next section was devoted to aqueducts and water supply outside of Rome, presenting Pompeii, Tauromenion (Italy), Spalato (Croatia), Parion, the Şirince Aqueduct of Ephesus, Syedra (Turkey), Gerasa (Jordan), Sepphoris (Israel) and the pre-desert areas along the African Limes. The topic of the fifth section are toilets and baths: the toilets of Rome, the latrines of the baths of Caracalla, public baths in Late Antique Rome and the Roman baths of Parion (Turkey). Fountains was the topic of the sixth section with supply devices and water effects in Roman Imperial nymphaea, a fountain of a triclinium near the Temple Mount in Jerusalem, fountains in the Terrace Houses of Ephesus and the multi-sensory effects of water in Roman and Late Antique elite houses. The seventh section deals with hydraulic engineering: Frontinus' quinaria, the NOEmes aqueduct and castellum and planning and building an aqueduct without the use of surveying instruments. In the last section various topics were summarized with the feeling of water in Trajanian times, downdrains in Ostia and water machines in Medieval Arabic texts. The conference programme was impressively complemented by several full-day and half-day excursions. It offered the opportunity to visit monuments that are otherwise not accessible to the public. Once again it became clear that neither a lecture, nor a publication or pictures can replace the encounter with real archaeological findings. The presentation of new research results on ancient hydraulic engineering and the enhancement of knowledge by visiting comparative examples on site is the declared aim of this conference series.