I just had a Caitlyn tank Tower.
Sowhere midgame we were chasing enemy bot and I was about to engage the second lane turret when Caitlyn flashed, tanking it instead.
She only got one or two shots on target, so there wasn't much lifesteal, but all in all she took six or seven Tower shots and could have taken another before it got dangerous.
I remeber a time where three or four shots where well enough to kill any squishy at any time of the game. You actually needed armor to dive. But this was a Caitlyn calmly standing under tower fire.
The first tower is dangerous in the early game, but by the time you reahc the second twer those have fallen offso far to be a joke.
And you can actually take everything from the Inhibitor Tower to the Nexus in one go if the enemy is down.