Having just returned from a visit to Vila-real, I found this video especially interesting and hope you will as well. It's from the April 24, 1988 match versus Alzira, played at El Madrigal. Villarreal were in Segunda Division B at the time and challenging for promotion (they eventually finished second, but only the top team was promoted in those days; there were no playoffs).
The game itself is interesting for the quality of Villarreal's two goals (and the one waved off by the referee), who is quite amusing in the way he brandishes yellow cards, and of course Villarreal is playing in yellow shirts with blue shorts, as they did for many years.
Vila-real in those days had a population of about 40,000 compared to over 50,000 now, and of course 1988 is before Sr. Roig invested in the club and built the Sports City. El Madrigal held about 9,000 in those days, mostly all standing except for the tribuna, and the ground is of course quite low compared to today and the area around it was not built up as much. This picture is an aerial view from 1989 to help orient you--the main (north) stand is the only covered one, and the standing area to the right of the covered stand in this photo is now the stand where our banner is displayed.
There are trees almost in the southeast and southwest corners of the ground which are of course long gone, as these areas are now uncovered seating. The trees behind the east stand are gone now, and this stand is now the extremely high one (with the visiting fans' "bird cage") that serves as the ground's most visible feature.
I suppose the main similarity between 1988 and 2015 El Madrigal is really the constricted nature of the space available to build in along the length of the pitch. The 1988 main stand isn't very deep, and although this stand has been rebuilt since then, it's still hemmed in by the road alongside and buildings right up alongside. The south stand also uses up about every inch of space it can, hemmed in by buildings as well.
Also, the playing surface has been lowered several meters since 1988.
There are two mysteries: first, every reference I've seen reports the changing rooms were in the northeast corner in a separate building, but the players clearly enter and exit the pitch from a building on the southeast side of the pitch.
Second, it's not absolutely clear to me that the north stand in the video is the same as the north stand in the photo above. That one was supposedly opened in March 1988 with a friendly against Atletico Madrid, but I am wondering if that date is correct, or if it was opened a year later. The one in the video may be the same ( you can get a good view of it at 10:03 in the video) but it's hard to tell for sure.
If anyone knows, let me know! Enjoy and ENDAVANT VILLARREAL!