Single-walled carbon nanotubes are model one-dimensional structures(1-6). They can also be made into zero-dimensional structures; quantum wells can be created in nanotubes by inserting metallofullerenes(7), by mechanical cutting(8-10) or by the application of mechanical strain(11). Here, we report that quantum dot arrays can be produced inside nanotubes simply by causing a misalignment between the nanotube and the < 100 > direction of a supporting silver substrate. This method does not require chemical or physical treatment of either the substrate or the nanotube. A short quantum dot confinement length of 6 nm results in large energy splittings.