The Instituto de Astrofísica de Canarias is holding open days at the Teide Observatory today and tomorrow, the tours to include the new facilities opened by King Felipe the other day (link). These are always popular events, and allow the public not only to see the telescopes, but to use them, as well as learning about the work the observatory does. The observatory will be open to the public between 10am and 3pm, and entry is free. The IAC reminds anyone thinking of attending that due to the terrain and altitude, the public should wear comfortable shoes, sunscreen and a hat, and also a jacket or coat. Those with heart complaints or breathing problems should note that the altitude is 2,300m, and so should check with a doctor before visiting.