Eucalyptus trees are probably the most underrated tree in RuneScape, requiring level 58 Woodcutting. Not only can players earn 120,000 coins per hour, but they can also get over 55,000 experience an hour. The best place to cut these is near Mobilising Armies, which also contains the bank. Without any bonuses, it takes ~77,637 eucalyptus logs to get to 99 Woodcutting from 58. This makes somewhere around the area of 31 million coins in that time. Recently the price of the logs have dropped so they are not as good for money making.