The weird thing is that it differs from your perspective. If you're looking in from "infinity" (ie. where the gravity field of the black hole is negligeable) th

The weird thing is that it differs from your perspective. If you're looking in from "infinity" (ie. where the gravity field of the black hole is negligeable) there appears to be a region where nothing can get to : the event horizon. After all, what does one see when looking at a light source falling into a black hole. That light source slows down as it approaches the event horizon. When it gets close you'll see it dim. That's because time is going slower for that light source. Also it becomes smaller and smaller. It will never cross the event horizon, which is the point where time would stop and it's size would be zero. Because of the amount of time it takes to actually get there, one can semi-accurately refer to it as the end of time. The weird thing is that the end of time is a spherical region of actual space, not a point in the future. Because this only happens close to the black hole it'll likely look confusing : it would fall very quickly to the event horizon, ever accelerating, then suddenly every 50% reduction in distance between it and the event horizon takes 100% more time to happen. If you're the one falling into a (large) black hole you'll see the opposite : the rest of the universe will go faster, grow brighter, and grow bigger (since the universe is mostly empty space and you can't really tell the physical size of stars from a distance you'd mostly see the empty space being bigger and may think everything else is the same size. It's not though, you just can't tell the difference between 10e-50 degrees and 10e-48 degrees). The event horizon is a theoretical concept, there is nothing in space that corresponds to the event horizon. No obstacle, no marker, no force, no nothing. From up close, it's just empty space. Think of the path between you and the rest of the universe, that path is getting longer, and you can see and measure that. That's all that happens, nothing more. Everything you can reach is falling in as well, and you see the distance between you and other things falling in increasing just the same. If you were to go anywhere, you'd notice that the distance between you and wherever you're trying to go grows bigger with time. If that happens fast enough you can never get there, because the distance will never decrease. The weird thing is that that is true for us here on earth as well. The distance between us and everything outside of our local galactic group (everything contained by a few galaxies who are bound by gravity. Granted, this structure is several million lightyears across, but it is finite and very tiny compared to the total universe) is getting bigger and further away. The vast, vast majority of the universe is expanding, exactly like you'd expect to see if you were falling into a (extremely huge) black hole. Furthermore the edge of the universe is suspiciously close to where those "hallways" expand at superluminal speeds (ie. the rate of distance increase between us and the faraway object > c). The distance between the furthest object ever measured and the point where distance increase speed becomes superluminal is 400 million light year. That seems suspiciously close to be coincidental. So the answer for "big" black holes might be very simple. What's inside ? Look around you. That's what's inside. Certainly some black holes are of a size that you could conceivably throw a solar system inside, and nothing out of the ordinary would happen to it at all for a very long time, essentially for the lifetime of the black hole, which can be hundreds of billions of years. That leaves small black holes where you'd be torn to shreds by the difference in gravity between the closest part of you to the black hole and the parts further away. It'd be like falling while having rockets accelerating your feet downwards. At some point, those rockets accelerate fast enough to rip your feet clean off. However, small black holes evaporate through Hawking radiation. They quickly convert all their mass to energy. So there'd be a massive explosion happening below you, which will likely vaporize you long before the tidal forces become an issue.