The Spikes in these ruins throw spiked bars. You can get the Super Bell here and climb up the walls, so you can better avoid the Spikes. Go up the slope with the Spikes, then go left for the stamp. To the right is a pipe. There are ! switches to clear with many Spikes above the switches. Use the Game Pad to clear the switches safely and get ride of the Spikes. This will make the first Green Star appear. Go past the Goombas and you'll reach the midpoint, which is in front of some pendulums with spike bars rolling on them. Go past the pendulums and run up the long slope. You can get Red Coins here. There are spike bars, some of them long, rolling down the slope. Try to keep the Super Bell as you make your way to the top. There are three Spikes at the top. At the top, climb up the wall to the left for the second Green Star.
Drop back down and you'll find moving platforms with spike bars. The third Green Star is over a platform to the left. Be sure to adjust your camera angles to make jumping easier. After a few more platforms, you'll reach solid ground. You'll have to run up another slope with a Spike at the top, which is in front of the flagpole.
The stamp is of a Spike holding a spike bar.