It's been 10 years since we celebrated 50 years of speleology around Matienzo, so the next party is being planned. Details of the preliminary programme for the "Gran Fiesta" weekend are online. http://www.matienzocaves.org.uk/history/60years/index.htm
The link can also be found at the bottom left of the Matienzo Caves Project website front page. http://www.matienzocaves.org.uk/page1.htm