Centre Aquatique Au Fil de l'O

Au fil de l'O is the aquatic centre of Saint-Genis-Pouilly, at 20 rue René Cassin, 01630 Saint-Genis-Pouilly, in the Pays de Gex on the Franco-Swiss border. It is operated under delegation by Vert Marine, which runs many French pools. Its internal rules call the building "Le Centre Aquatique Au Fil de l'Ô".

The water is plain treated pool water. The operator claims no spring, thermal source, mineral or brine water; the wellness area is heated balneo water, not thermal water. The installations are a 25-metre sports basin with a movable floor, a leisure basin of 125 m², a paddling pool, water games, a large slide, an outdoor basin and an outdoor aquaplash play feature with relaxation areas. The house rules name three separate outdoor bathing areas — an outdoor leisure basin, an outdoor sports basin and an aquatic river — where the operator's list of pools names a single outdoor basin. The slide is barred to children under eight and under 1.20 m.

The wellness space is a separate area reserved for adults over 18, with a sauna, a hammam, a solarium, a wellness basin, massage showers and a herbal-tea room; the house rules describe the same area as balneo pool, sauna, hammam, rest room and massage showers, and note that swimming is not permitted in the balneo basin. Entry is with a wristband issued at the desk.

The centre is open all year with three separate timetables for term time, short school holidays (zone A) and the summer holidays, and with different hours for the sports basin, the leisure-and-slide area and the wellness space. In term time the pool opens Monday 12:00–19:45, Tuesday 12:00–13:45 and 17:00–20:45, Wednesday 12:00–19:45, Thursday 07:00–08:30, 12:00–13:45 and 17:00–19:45, Friday 12:00–19:45, Saturday 14:30–18:15 and Sunday and public holidays 09:00–12:45 and 14:30–18:15; holiday timetables run longer, up to 10:00–19:45 daily in the summer. Aquagym, aquacycling, aquacrosstraining, a swimming school and baby-swimming courses are also offered.