Demjén's Spa is pretty average and if it wasn't for the possibility of night bathing (until 2am every night), then I wouldn't have included it on www.ieger.com.
The baths seem to be stuck in some sort of time warp, tacky is the word that comes to mind but that doesn't really cover it. I believe that when the Demjén complex was built, those bankrolling it wanted to recreate a Roman bathing experience hence the pillars, tiled roofs and mosaic inlaid walls.
As it is, it doesn't offer anything that other baths in the Eger region don't do bigger and better except for the aforementioned night bathing - there really is nothing quite like enjoying a glass of wine, soaking in the warm mineral waters and all the while gawking at the starlit skies.
Second-rate is the adjective that comes to mind
Negative thoughts aside, the baths consist of 6 outdoor pools of varying temperatures, two indoor pools (a 25m swimming pool and a children's paddling area), all the pools are fed by the local thermal waters bubbling up from more than 600 metres below the surface.
In the summer, children and those young at heart can enjoy the Kamikaze Slide, rubber ring 'rafting', a multi-slide and the diving pool with boards at three separate heights.
Night bathing is something that has to be experienced
As of 2013, a new cave spa has opened which tempers some of my criticisms above as it adds a whole new angle to the place. There are 5 slides with a combined length of 550 metres.
As well as its recreational focus, this new construction also houses 12 new spaces dedicated to health tourism (massage and the like) and there is even a pool specifically for those with physical disabilities.
The water here is indicated for various conditions, most notably arthritis, rheumatism, inflammation, gout, post-surgery etc.
Demjén's Cave Baths are man-made not like those at Miskolctapolca
The baths are open every day from 09.00-02.00. However, individual facilities have their own opening times.
Wellness area and indoor pools
If you want to stay in Demjén, although I don't know why you would when Eger is but a short distance away, then there are a couple of good options.
The Cascade Hotel, which is part of the bathing complex, has a luxurious tinge and is very handy for the spa, the four star Eger Korona Borház, despite looking like an unattractive block of flats is also worth a look.
A less impersonal option is the Pásti Vendégház (only in Hungarian) which has three comfortable apartments to rent and is a cheap alternative to the two beasts above.