Cut the watermelon flesh into bite size pieces. Combine the syrup ingredients in a shallow pan, bring to simmering point and briefly poach the peach slices. Remove them with a slotted spoon and reserve the syrup. Arrange the fruit and almonds in a serving dish. Heat the syrup to boiling point, then simmer until reduced by half. Cool a little then pour over the fruit mixture. Chill well before serving.