How do i capture places like lakes on Evony-Free Forever?

Someone said to scout then attack, but when i do that my troops automatically come home as soon as they get there. Also i only attacked it because nobody else controls it and it’d help me alot

If your troops come back without capture the valley or flat, this is why your Town Hall need more upgrade. The more you upgrade your Town Hall, the more valleys and flats( one for each upgrade ) you can get.