https://www.haaretz.com/israel-news/.premium-gaza-s-refugees-have-always-haunted-israel-now-they-re-on-the-march-1.5958265?=&ts=_1524320006239
This is a quite useful article from Haaretz just before the Great Return Marches started on March 30th which elaborates the reasons why the right of return for Palestinian refugees is so imperative & immediate. There are 8 refugee camps with over 1.2 million registered refugees in Gaza within a very small geographical area. Since so many homes in Gaza have been bombed by Israel, there are likely thousands more displaced who are not registered with the UN. There are 19 refugee camps in the West Bank with close to a million refugees & also refugee camps in Jordan, Lebanon, & Syria. Many living in the 13 Syrian camps had to flee the bombing & it’s not certain where they fled since Jordan closed the borders to Palestinians from Syria. The Syrian regime is now bombing one of the largest of these at Yarmouk, claiming that terrorists are holed up there.