During inspection of a renovated home originally built in 1963, we discovered a 3 ft by 3ft raised concrete platform near the base of the basement stairs. The inspector did point out that the raised platform is underneath the sewer line, not sure if that is pertinent. Also, the platform is located directly below an opening to a crawlspace which runs under an addition on the original home. We are not sure what this was built for or what it may be covering up. The current owner as well as the architects plans for 1999 renovation done on the original 1960's home do not reveal why this was built. Please give us your thoughts on what this may be and/or how we can find out what it is?