Lots of stories in the Guardian, if you search. They all live in northern Sumatra. There are also rhinos on Java.

Do you have any contacts to share of the guesthouse guy? I read on other thread that his name is Jali, is it correct?
If you went alone I guess there were easy to follow paths, because when I went deep i the jungle with guides it has always been to places where I would have had no idea how to come back. Also here I'd like to go deep and Kedah seems to be the best place to do that, I think a couple of nights in the jungle would allow some interesting night life spotting as well.

Regarding tigers and rhinos, it would just be a nice bonus, not something that I really expect to see.
For the elephants I meant Tangkahan but I guess here the chances to be disappointed are pretty high.
The elephants here are domesticated and kept in one place.

Do you know if there is an easy way to get there from Kedah? If I pass by I might stop just to see them since I have never seen elephants but I am not going to travel days to see zoo style elephants. Furthermore, are there any ethical reasons why I shouldn't give money to this center? I read the elephants were used in the past against loggers and now they are just there but I am definitely against taking them out of the wild to entertain tourists, if this is the case I don't want to support with my money.
The place with the elephants is close to Medan. It's a long, long way from Kedah. There's no direct route through the national park (except on foot!).
Yes, the man who owns the guesthouse in Kedah is Mr. Jali. I don't have his phone number. I'm not sure how good his English is either, but he obviously manages somehow. I spoke to him in Indonesian though.
The paths in the jungle around Kedah aren't that easy to follow. I'm experienced at hiking in jungles, and know how to not get lost. If you don't have the right orienteering skills, it would certainly be possible to get lost by yourself on the trails there.

Do you know if there is an easy way to get there from Kedah? If I pass by I might stop just to see them since I have never seen elephants but I am not going to travel days to see zoo style elephants. Furthermore, are there any ethical reasons why I shouldn't give money to this center? I read the elephants were used in the past against loggers and now they are just there but I am definitely against taking them out of the wild to entertain tourists, if this is the case I don't want to support with my money.
It's 3.5 hours each way approx. Medan, so that's the journey, no connection to Kedah. It's close to Bukit Lawang, so these are usually combined
There was also a much wilder elephant place at Aras Napal, in the same general area as Tangkahan (a bit further north), which you visited by going up river on a canoe.
However it seems this may have failed
http://webcache.googleusercontent.com/search?q=cache:qdOUdk92dvcJ:www.leuserfoundation.org/index.php/news/188-ecotourism-opportunity-sumatran-elephant-in-aras-napal-242+&cd=1&hl=en&ct=clnk&gl=uk
http://www.thejakartapost.com/news/2016/12/10/elephants-suffering-from-malnutrition-sent-to-sanctuary.html
This is a fairly typical story of the various elephant sanctuaries - the elephants are relocated and tamed, due to deforestation/loss of habitat and their coming into conflict with humans - then the sanctuary over time is either encroached on by neighbouring villages, or the elephants die of disease and/or malnutrition due to lack of funding
For the elephants at Tangkahan this isn't the case - they are relatively rolling in cash from visitors, so the elephants are in better condition. As far as a conservation venture goes I don't know if they are really seriously patrolling, but the tourist $$$ do provide an income for local people and keep the elephants alive.
There is some Western input at Tangkahan, and they are trying to wean people off elephant rides, which are no longer considered acceptable by Western conservation groups (Indonesians could honestly care less), and are now offering a 'walking alongside elephants' 3-hour trip, which is designed to raise more money than the brief 'elephant bathing' does.

Great piece of info "Thelawnet", thank you!
Does anyone have any info/suggestion about the Harau Valley, is it worth it or is it very touristy? It is quite out of the itinerary but then Padang is very close and it is easy to fly out. Any chance for authentic experiences there?
Lots of stories in the Guardian, if you search. They all live in northern Sumatra. There are also rhinos on Java.
Thanks for the link, Giora. I know they say there are Rhinos on Java, but as far as I know, only in Ujung Kulon NP. This is a rather small NP, and very secluded from the rest of Java. One would think that the seclusion provides some protection. Anywhere else in Java, I see no chances at all for rhinos to survive in the wild. And even for Ujung Kulon, I have doubts, because I read several reports (blogs etc.) of people who went there to see the rhinos - with NP rangers, who should know where they would find rhinos in the park -, but did not see any. This leaves some doubt if there are really any left (at least for me). Also I read repeatedly that some Chinese and / or Vietnamese dealers pay high prices for rhino horn. There also scientific reports who mention Sumatra and Kalimantan as places where there are still wild rhinos, but not Java.
Leuser NP is larger, but not as secluded, and I haven't read many reports of people who actually saw rhinos or truely wild living elephants there (let alone tigers).
Hey federicom, I hope you do go there and wish you all the best to see all sorts of wildlife while you're there. And I hope you report back here - or do you write an own blog? Then please link it here. Thank you!
Tigers are sometimes spotted in the Gunung Leuser NP -- but the odds of spotting them are bad. Others see them first. http://www.thejakartapost.com/news/2017/12/14/prosecutors-demand-three-year-prison-sentence-for-trader-of-sumatran-tiger-skins-organs.html
Paul