IMAGES will not fall into 2 columns

/********************************
      GENERAL
******************************** */
body{
  font-family:'Open Sans', 'sans-serif'; 
}


#wrapper {
  max-width: 940 px;
  margin :0 auto;
  padding: 0 5% ;
}

a {
 text-decoration: none; 
}

img {
  max-width: 100%;
}




/********************************
      HEADING
******************************** */


#logo {
  text-align: center;
  margin: 0;
}

h1 {

font-family: 'Roboto', sans-serif;
margin:15px 0;
font-size: 1.75em;
font-weight:normal;
line-height:0.8em;
}

h2 {
font-size:0.75em; 
  margin: -5px 0 0;
  font-weight: normal;
}



/********************************
     NAVIGATION
******************************** */


nav {
  text-align:center;
  padding:10px 0;
  margin:20px 0 0; 
}




/********************************
     FOOTER
******************************** */

footer {
font-size: 0.75em;
  text-align:center;
  clear:both;
  padding-top: 50px;
  color: #ccc;

}

/* *******************************
     PAGE: PORTFOLIO
******************************** */



#gal{
  margin: 0;
  padding: 0;
  list-style: none;
}

#gal li {

 float: left;
  width: 45%;
  margin: 2.5%;
  background-color:#f5f5f5;

}


}

/* *******************************
      colors
******************************** */


/* ---site body--*/

body {
background-color:#fff; /*white*/
color:#599a68     
}

/*green header*/

header {
background: #6ab47b; 
  border-color: #599a68; 
}

/*nav background on mobile*/
nav {
background:#599a68;
}

/*logo text*/
h1, h2 {

color: #fff;
}

a {
  color: #fff;
}


}

/*nav link*/
nav a, nav a:visited { 
  color:#fff;
}
/*g selected nav link*/
nav a.selected, nav a:hover {
  color:#32673f;
}