1 INTRODUCTION  
2 THE SAMPLE  
2.1 The GOODS NICMOS Survey  
2.2 Source Detection and Catalogue Cross-Matching  
2.3 Photometric Redshifts  
2.4 Stellar Masses and Rest Frame (U-B) Colours  
2.5 Colour and Completeness Limits of Red and Blue Galaxies  
3 GALAXY ENVIRONMENTS  
3.1 Fixed Aperture Densities  
3.2 Nearest Neighbour Densities  
3.3 Monte Carlo Simulations  
4 RESULTS  
4.1 Galaxy Local Densities  
4.2 The Colour-Magnitude Relation at Different Stellar Masses and Local Densities  
4.3 Colour-Mass and Colour-Density Relations  
4.4 Galaxy Properties in the High and Low Quartiles of Density and Mass Distribution  
4.5 Is the Colour-Density Relation Caused by Variations in Stellar Mass?  
4.6 The Environment of the Most Massive Galaxies and Its Relation to Galaxy Sizes  
5 SUMMARY AND CONCLUSIONS