Hi, here is my initial entry for your consideration. I'm not sure that this is what you're looking for, but I had an idea and ran with it. I thought about how a capital T and capital L are nearly the same shape, rotated (the T would merely need to be missing the right arm). So, I made a symmetric lettermark for TL, and I reversed it out of a circle to create this effect. The essentially amorphous shapes in the upper right and lower left, in two shades of blue, can represent twin lakes. In addition, the combination of the T and L creates a space between the letters, and a roman numeral two (as in twin) is also formed. Thanks for your consideration!
(This comment references Entry #1)