NGC 3079

is a remarkable edge-on spiral galaxy. It is optically disturbed and dusty, has a Seyfert2/LINER spectrum, an active nucleus, and starburst activity (for a summary see Baan & Irwin 1995, and references therein). Two radio lobes extending approximately along the minor axis of the galaxy -- very similar to those in Circinus (see below) -- suggest the presence of outflow (e.g., Duric & Seaquist 1988; Hummel, van Gorkom & Kontanyi 1983). This is also indicated by the H$\alpha$ images which reveal a giant loop (Ford et al. 1986) and, on deeper images, several filaments on kpc scales (Armus, Heckmann & Miley 1990). The nuclear activity may be fuelled by an inner molecular disk (Young, Claussen & Scoville 1988) which has a radius of $\sim$400 pc. Broad HI absorption lines detected by Irwin & Seaquist (1991) probably indicate a fast-rotating ring of similar size. High-resolution VLA HI and OH absorption measurements by Baan & Irwin (1995) reveal numerous components, one of which is a rapidly rotating compact disk, extended by about 100 pc or 125 (see also Gallimore et al. 1994). NGC 3079 also contains the most luminous known H₂O megamaser.