Basic Question-Tourist Visa (Medellin)

I know this is so basic, but is proof of a round trip ticket required upon entry in Colombia if trying to get a tourist visa? I am going to Medellin to familiarize myself with the area and explore some potential opportunities while I am there. Any suggestions as to what documents to bring that would prove of value for a tourist visa? Or any copies of documents that are important to have available while I am there? Thank you.