Im Bildhintergrund CSS festgelegt
#hero1{
background:url(https://4.bp.blogspot.com/_AQ0vcRxFu0A/S9shDGGyMTI/AAAAAAAAAYk/kn3WTkY2LoQ/s1600/IMG_0714.JPG);
background-size:cover;
background-position:center center;
background-attachment:fixed;
Nasty Nightingale