I believe the nav menu is within the <header> section. In the header.php file.
Here is the code for the header.php document:
<header id=”site-header” class=”group” role=”banner”>
<?php
// Get header image:
$header_image = get_header_image();
// Get text colour (or lack thereof):
$text_color = get_header_textcolor();
?>
<?php
// Has the text been hidden?
if ( ‘blank’ == $text_color ) { echo ‘<div id=”header_image_margin”>’; }
else { echo ‘<div id=”header_margin”>’; }
?>
<div class=”header-container group”>
<hgroup id=”header-title” <?php /* if ( $header_image ) { echo ‘class=”header-image-true”‘; } */ ?>>
<h1 id=”site-title”>” title=”<?php echo esc_attr( get_bloginfo( ‘name’, ‘display’ ) ); ?>” rel=”home”><?php bloginfo( ‘name’ ); ?></h1>
<h2 id=”site-description”><?php bloginfo( ‘description’ ); ?></h2>
</hgroup>
</div><!– .header-container –>
</div><!– #header_margin or #header_image_margin –>
<?php
// Check to see if there is a custom header image
if ( $header_image) :
echo ‘<div id=”header_image”>’;
// Compatibility with versions of WordPress prior to 3.4.
if ( function_exists( ‘get_custom_header’ ) ) {
// We need to figure out what the minimum width should be for our featured image.
// This result would be the suggested width if the theme were to implement flexible widths.
$header_image_width = get_theme_support( ‘custom-header’, ‘width’ );
} else {
$header_image_width = HEADER_IMAGE_WIDTH;
}
?>
” title=”<?php echo esc_attr( get_bloginfo( ‘name’, ‘display’ ) ); ?>”>
<?php
// The header image
// Compatibility with versions of WordPress prior to 3.4.
if ( function_exists( ‘get_custom_header’ ) ) {
$header_image_width = get_custom_header()->width;
$header_image_height = get_custom_header()->height;
} else {
$header_image_width = HEADER_IMAGE_WIDTH;
$header_image_height = HEADER_IMAGE_HEIGHT;
}
?>
<img src=”<?php header_image(); ?>” width=”<?php echo $header_image_width; ?>” height=”<?php echo $header_image_height; ?>” alt=”” />
<nav id=”sub-access” class=”group” role=”navigation”>
<h1 class=”assistive-text section-heading”><?php _e( ‘Main menu’, ‘anaximander’ ); ?></h1>
<div class=”skip-link screen-reader-text”>“><?php _e( ‘Skip to content’, ‘anaximander’ ); ?></div>
<?php
wp_nav_menu( array( ‘theme_location’ => ‘header_menu’, ‘menu_class’ => ‘nav-menu’ ) );
?>
</div>
<?php endif; // end check for removed hea