When I reopen the project on Visual Studio, I only found solutions of it in the format .sln, someone could explain to me how fix this?

Question

after creating a web site in visual studio 2015 and adding some items, I save the project and then close visual studio. When I reopen the project on Visual Studio, I only found solutions of it in the format .sln (and not my filee in format .aspx), someone could explain to me how fix this problem? I'd like to see all the items I created and not only solutions!