Danube Bend (Dunakanyar), and Duna-Ipoly National Park North of Budapest

This model is based on SRTM 90m projected in WGS84 at 1:200000 scale when printed at 210mm x 250mm x 5.7mm (Like on a Prusa MK4). This means at the designed scale, 1cm on the model represents 2km. The horizontal contour bands represent 100m contour intervals. I've printed it without vertical exaggeration, but if you like to show the terrain slightly more extreme then ramp up the Z scale.

Source:

Jarvis, A., H.I. Reuter, A. Nelson, E. Guevara, 2008, Hole-filled SRTM for the globe Version 4, available from the CGIAR-CSI SRTM 90m Database (http://srtm.csi.cgiar.org).

Variable Layer Height

I used variable layer height to ensure that closest to the river the detail was ultra fine at 0.05mm layers. Before and after I expanded that to 0.1mm. The lowest green is slightly transparent which has been used to create the nice gradients above the river and the striking style above the first contour line.

Attribution:

Inspired by @IgnisVeneficus (2020), Topographic 3D Map - Danube Bend (Dunakanyar), CC BY 4.0, this version used the original source data in GIS software to adjust the extent to include more of the river and was prepared for a standard scale. No-commercial re-use is a requirement of one of the software licences I have used.

The colours were inspired by satellite pictures that show much of the peaks are covered in forest and the farmland, towns and villages along the river banks. There is a list of satellite imagery, attached to the Danube Bend Wikipedia page here: https://geohack.toolforge.org/geohack.php?pagename=Danube_Bend¶ms=47_47_57_N_19_05_30_E_region:HU-PE_type:waterbody_source:dewiki 

This version used the original source data in GIS software to adjust the extent to include more of the river and was prepared for a standard scale. The height of the Danube river was reduced to 80m from between 96-101m so that using scheduled colour changes the river could be printed in a different colour to the rest of the print. Visually the effect is about 0.1mm lower at the upstream end (West). The source data has 90m resolution approximately 0.45mm at 1:200,000.