The collection De Cock contains the only known drawings and sketches made on Java by Christoffel de Wilde. It includes 23 drawings and three studies in oil. One of the drawings is the portrait of a young man. This young man could possibly be De Wilde’s eldest son, Andries, but this identification is only a conjecture, since the portrait is not annotated. With the exception of one sketch, the drawings and studies depict landscapes in the Preanger region (Priangan), the mountainous Sundalands of West Java, where Bandung – only a small 'negorij' back then – is currently the largest city. The images picture landscapes and detailed views on waterfalls. There is also one sketch which gives an impression of the daily life. It depicts a small orchestra and two female dancers. 19 out of the 24 topgraphical images have been annotated by De Wilde, 15 of those have been dated and one is signed by 'C. de Wilde'. The dates range from 20 March to 12 October 1819. This collection is relatively homogeneous and offers a valuable insight into De Wilde's travels north and south of Bandung. Nevertheless, the image is only partial, both in space and in time, as De Wilde has lived in Java much longer than the period that was indicated, and he has also seen much more of the island than only the places that are depicted in the drawings.