From Senaru, which is to the north of the mountain, I headed south through rainforest, climbing from Senaru at 600m to the crater rim at 2600m; the ascent was tiring, but it was a simple case of putting one foot in front of the other. I passed three very basic mountain shelters, known as Pos I, II and III on my map, but soon enough I reached the rim, where the most incredible views opened up in front of me. For the first night I camped right there on the rim, overlooking the inside of the crater, with its beautiful lake and second, still-smoking cone (the latter being the result of a recent eruption in 1994). The whole place was stunning; suffice to say that I have never seen a sight quite like the crater of Rinjani, even in Tongariro, and it was worth the six-hour uphill struggle just to see that view.
Delightful though the walk up to the rim was, it didn't take me long to spot Rinjani's biggest problem. Indonesians have absolutely no concept of litter; to them the world is a dustbin, and as a result Rinjani often looks more like Binjani.
There is shit everywhere, both figuratively and literally; because there aren't any toilets in the park (not that you would expect any) there are piles of toilet paper and the associated dried masses behind every outcrop and tree, and the tracks are piled with litter, dropped by guides and locals alike. This applies throughout Indonesia; on the ferry to Lombok, people just threw their rubbish overboard and nobody seemed to care, but the effect is a bit more obvious in the natural environment of a volcano.
It's probably a result of there being little ecological awareness here – being green is, after all, a luxury only afforded by the rich West – but I still packed out what I packed in, being careful not to add to the pile of sweet wrappers and plastic bottles that threatens to choke the park; one day the attitude might change, but in the meantime I would even discover that there are discarded cigarette packets and biscuit boxes on the summit, at 3726m.
By all accounts the problem is worse in people-heavy areas like Java. It really makes you appreciate how clean the western world is, even places like London where people complain about the mess. This, rather than the incredible views, is one of the most striking impressions of Gunung Rinjani, and it's a terrible shame.