Portals, Stargates & Vortexes: Time Travel Possibilities

I have always been interested in Time Travel since the days of H.G. Wells and "The Time Machine".   In the last 30 years, I've explored various topics around time travel and Quantum Physics.   One of my fascinations is the possibility of real Portals around the world that can show us a glimpse of other dimensions.   One of those could be the spirit realm, another could be a hint from the past or future.  I've read many stories of people going into other dimensions or having strange experiences around ley lines, portals and vortexes.   I'm going to explore a few of the places and experiences that might help us understand more about portals, star gates or wormholes.