It is far more likely that you will have heard of these websites long before you will have heard of this one but in the unlikely event you haven't, here are some other sites which I think provide great content. It's too bad they themselves don't link similiar/interesting sites because there's a lot of cool content out there but as I slowly discover them I will add to my list here (and please recommend others!):
Kurzgesagt – In a Nutshell
These guys produce fun, short, but very informative videos on a huge variety of topics. They are a great way to obtain a basic understanding of a potentially complex topic in a format that accessible to everyone.
Wait But Why
The WBW team produce great content on a lot of interesting topics. My only qualm is that sometimes the posts are quite verbose such that reading can feel like a chore, but they do a great job at covering things at a depth that you won't really find anywhere else other than in a formal research journal (which aren't usually as fun to read).
There's already enough TED content for a lifetime of watching videos, so filtering and finding the ones most relevant to you is an art. But at its core TED represents what I want to accomplish: to discuss ideas worth spreading which can push humanity forward.
Sam Harris' podcast
Sam Harris is a great writer and one of the few people I admire for their intellectual rigor and commitment to bettering humanity. His books and podcasts are worth checking out.
More to be added later!