Bromo is not the tallest volcano on Java, nor the most dangerous. It is simply the most photogenic thing on the island: a smoking cone sitting inside an ancient caldera floor of grey volcanic sand, with Semeru venting on the horizon behind it.
The classic approach is a pre-dawn jeep to a viewpoint on the outer rim, then down across the sand sea and up 250 steps to the crater edge. It is cold — genuinely cold, near freezing before sunrise — and almost nobody packs for that.
The Tengger people who farm these slopes have lived here since before the Majapahit collapse, and their Yadnya Kasada ceremony still ends with offerings thrown into the crater.