El Teatro Colón is a National Monument and place of great cultural and historical significance for the people of Bogotá. It was designed by Italian architect Pietro Cantini and was first inaugurated in 1892. In 2008 the theater closed for rennovations, re-opening again in 2014. The six year restoration project included new electric & hydraulic systems, flame restardant seating, restoration of some of the artwork and the original colours (yellow & salmon), as well as the removal of a chandelier made in 1948 in favour of the original.
The theater is very impressive and yet few visitors even know it exists, let alone residents. It has recently become the new home of the National Symphony, but is also host to a variety of local & international acts. Below you can see an image of Fonseca performing with the Symphony at a concert in December 2014.
The only way to get a peek inside is to actually purchase tickets for a show. The ticket office is open Mon-Fri from 10am to 8pm and on weekends and holidays from 9am until the start of the show. Ticket prices start at COP $10,000 (US $5) for gallery seating, so it's really quite affordable.
If you're looking for some romance and relaxation, you can even splurge by staying next door at the Hotel de la Opera, a beautiful colonial-style hotel in the heart of the historic district.
For more information on the opera house you can visit their website http://teatrocolon.gov.co/