If you are planning to make some changes around your home and you want to add something new and interesting, you are on the right places. A modification that 100% of homeowners should consider? Adding a secret room or passageway somewhere inside. Not only will it make your house a bajillion times cooler, but then you can start playing pranks on your guests. The most popular trend found in this roundup is a room hidden behind a bookcase that seems to be the most practical one to implement too.